pts.visual.rgbimage._CubicSpline Class Reference

An instance of the CubicSpline class implements a function \(y=f(x)\) composed of three cubic spline segments of the form \(y=ax^3+bx^2+cx+d\). More...

Public Member Functions
def	__init__ (self, point1, point2)
def	ay (self, x)
def	y (self, x)

Public Attributes
	a1
	a2
	a3
	b1
	b2
	b3
	c1
	c2
	c3
	d1
	d2
	d3
	x1
	x2

Detailed Description

An instance of the CubicSpline class implements a function \(y=f(x)\) composed of three cubic spline segments of the form \(y=ax^3+bx^2+cx+d\).

The function is constrained as follows:

• the function is defined only for \(x\) values in the interval [0,1]
• the function goes through the four points \((0,0),\,(x_1,y_1),\,(x_2,y_2),\,(1,1)\) with \(0<x_1<x_2<1\), where the outer points are fixed and the inner points are provided as arguments to the constructor
• the function's first and second derivatives are continuous at the inner points
• the function's second derivative is zero at the outer points ("natural bounding conditions")
• regardless of the form dictated by the spline segments, the \(y\) value is always clipped to the interval [0,1]

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The documentation for this class was generated from the following file:

• rgbimage.py